As sensor-based technology has improved dramatically in recent years, new uses for sensors have become possible. In particular, cameras have become widely utilized for various applications. For many of these applications, it is desirable to minimize the size and weight of the camera to allow for deployment in tight spaces and to minimize costs of the camera. Additionally, although many cameras utilize moving parts to capture images, it is desirable to avoid use of moving parts where possible to ensure reliability of the camera.
One type of camera that may be utilized in many applications is the thermal infrared camera. Thermal infrared (IR) cameras capture image wavelengths in the range of seven and a half to fourteen micrometers. A typical IR camera uses an infrared sensor (or detector) to detect infrared energy that is guided to the sensor through the camera's lens. IR cameras can be utilized for a variety of imaging applications including, but not limited to, passive motion detection, night vision, thermal mapping, health care, building inspection, surveillance, and the like. Recently, an attempt has been made in the IR industry to integrated IR cameras in advanced driver assistance systems and autonomous vehicle systems.
One type of IR sensor is an uncooled Far-Infrared (FIR) sensor having a small form factor. Such sensors can typically be mass-produced using low-cost technology. In a typical arrangement, an uncooled sensor does not require a cryocooler for proper operation, but does require a shutter for frequent calibration. A shutter is a mechanical element placed between the lens and the FIR sensor for alternately blocking and exposing the sensor to infrared wavelengths. Generally, a shutter includes a flat-bladed flag, a sleeve, and an arm that connects the sleeve to the flag. The flag opens and closes at predefined time intervals. Alternatively, the shutter may be operated using an image quality algorithm.
While using a shutter may improve the quality and accuracy of the thermal image captured by a FIR sensor, having a black period of tenths of a second is not acceptable in certain applications. For example, using a shutter-based FIR camera in advanced driver assistance systems and autonomous vehicle systems can pose a high risk, as the camera must frequently shut off for a few hundreds of milliseconds. In addition, shutters include moving parts that wear out over time. This may cause a camera malfunction during driving and shorten the life time of the camera.
The FIR camera designed for advanced driver assistance systems and autonomous vehicle systems should meet additional constraints other than safety. Such constraints include a small form factor, accurate and low latency image processing, and low-power consumption. For vehicle-based uses, it is typically desirable to minimize the form factor of the camera to avoid interference with the driver's view or with vehicle systems, to minimize the manufacturing costs for the camera, to minimize fuel costs, to minimize maintenance required for the camera, to open up new possible locations for camera placement, and for other reasons.
Existing solutions face challenges in reducing form factor of cameras and, in particular, infrared cameras. Although solutions involving reduced form factor infrared cameras exist, such solutions often face other challenges with respect to heat dissipation, image quality, and more. Thus, when the size of the camera is decreased, the performance of the camera typically degrades.
Further, many existing solutions utilize various non-integrated electrical components, thereby requiring multiple sources of power in the form of printed circuit boards and power supply voltages. Accordingly, existing solutions often result in complex and costly manufacturing processes.
It would therefore be advantageous to provide a solution that would overcome the challenges noted above.